Machine for staking



2 sheets-sheep 1l (No Model.) y l A W.V1VI. HOFFMAN. l A MACHINE POB. STAKING,' S'TRETGHI-NG, AND SOPTENING LEATHER. Patented Feb. 14, 1888.

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. (No ms.) vl v 2 sheets-sh'eefJ l v I W: M. HOFFMAN.. y MACHINE EUR 'STAKING, STEETGEING, AND SOETENING LEATHER.

No. 378,066. 'Patented Feb. 1-4, 11888. Eig. 3.

Inventor.

' "in" Witnesses.

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'WILLIAM M. HOFFMAN, OF DETROIT, MICHIGAN, AssIeNOn ro THF HOFFMAN MAOHINF COMPANY, OF MICHIGAN. f

MACHINE FOR STAKING, STRETCHING, ANDfSOFTENING LEATHER.

sPncIFrcATroN forming pm of Leners Patent No. 378,066, dated February 14,1888.

Y Application tiled July 2, 1887. Serial No. 243,286. (No model.) Y

To all whom, it may concern:

Be it known that I, WILLIAM M. HOFFMAN, a citizen of the United States, residing'in Detroit, in the county of Wayne and State of Michigan, have invented certa-in new and useful Improvements in Staking, Stretching, and

Softening Machines, of which the following is a specification.

The object of my invention is to provide a rapid and` efficient means for stretching and softening leather, particularly that kind of leather used in the manufacture of gloves or shoes, andwill be fully and clearly hereinafter described and claimed, reference being had to the accompanying drawings, in which- Figure 1 is a side elevation.v Fig. 2 is a plan or top view. Fig. 3 is a side elevation vin sec tion through line A B, Fig. 4. Fig. 3fb is a detached front View of the stake-plate, and Fig., 4 represents a front elevation of the machine.

In both Figs. 3 and 4 the trcadle and mechanism connected therewith for adjusting the amount of stretching force to be given to the leather is left off, so that the other portions of the machine may be shown more clearly.

The staking, stretching, or softening operation is performed after the hide or skin is tanned. 'Ihe skin is first dampened, or .seasoned, as it is technically termed, and then rolled up and laid away overnight. This operation, if properly done, renders the skin slightly damp all through, but not Wet,- and prepares it for the stretching and softening process, and while passing through the operation it is stretched lengthwise, crosswise, orin any direction, which not only takes the stretch out of theleather, but renders it soft and pliable. My invention is designed to perform this operation quickly and thoroughly.

, In said drawings, 1 is the yframe of the-machine. It is usually made of wood and securedtogether in the ordinary way; but it may be made of cast-iron or 'any other suitable material. A semicircular bent wooden bar, 2, is

provided with abar, 3, for securing both ends,` and a block, 4, having a bar, 5, arranged parallel to the bar 3 and lirml-y or rigidly secured to it and the semicircular bar by bolts or in any well-known way. This construction leaves an opening, a, between the parallel bars 3 and 5. The Whole constitutes what may be termed a "semicircularstretching-bar,7 andis mounted upon a rock-shaft, 6, set .in bearings 7 on the frame 1. This stretching-bar is rigidly fastened to `the shaft 6 by an ordinary key or set- Y screw, and to one end is secured a crank-arm, 8, having a connectingrod, 9, pivoted thereto by a crank-pin, 10. At the back of the frame 1 are two boxes, 11, secured in place by bolts 12in the ordinary Way, in which is mounted the driving-shaft13,carrying the driving-pulley 14. At one end of the driving-shaft 13 is rigidly secured a crank, 15, having pivoted to it the opposite end of the connecting-rod 9. From this construction. it will be seen that as the driving-shaft turns it Will transmit, by means of the crank 15, connecting-rod 9, and crank-arm 8, a rocking or oscillating movement to the semicircular stretching-bar. T0 the bar 5,on each side of the bar, are pivoted,

by pins 16, the angular arms 17, having secured y between their upper portions (by screws or by any well-known means) a cross-piece or gripping-bar, 18. Thelower portions ofthe arms v17 are pivoted to connectingrods 19 by pins 20, which rods have their opposite ends pivoted to the angular` arms 21 by pins 2 2. These angular arms 21 are pivoted to a piece, 23,'

projecting down from the bar 5. The longer portions 24 of the arms 21 are made long enough to strike against the pins 25 when the semicircular stretching-bar is in the position shown in Figs. 3 and 4. To ,the pins 20 are pivoted the spiral springs 26, having their opposite ends secured to the bar 5 by pins 27.

From this construction it Will appear that .when the semicircular stretchingbar is in the v position shown in Figs. 3 and 4 the portions- 24 of the arms 2l will come in contact with the stationary pins 25 on the stake-bar and cause -the gripping-bar to open against the force of IOO allow the springs 26 to come into action andcause the g-i-nipirig-.trar-to tlnsanutsturly hold that portion'fof the skin placed 'therein while the other portion is undergoing the stretching operation.

The stake-plate 27 is preferably made of thin sheet-steel about one-sixteenth of au inch thick. It is semicircnlar at the top and is pro vided with a flat edge. (See Figs. 3 and 3".) This plate is secured by screws in the ordinary way to the stake-post 28, which post is rigidly fastened to the front cross-beam, 29, of the framel. At the front of the stake-post 2 8 are two bearings, 30 and 30, into which is fitted a vertical shaft, 31, having at the top a block, 32, adapted to lie and move against the face of the stake-plate. lar form, and its front face is 'made to incline from the front outward, as shown. Under the block 32 is aspiral spring, 33, to keep it up in its normal position. It is adapted to slide up or down in the bearings 30 and 30, and is kept in its upward position by the spring 33 when not otherwise acted upon. The block 32 is usually made of wood and the shaft 31 of iron; but any other material suitable for the purpose may be used.

On the rock-shaft 6 is mounted a frame, 34, (see Figs. 1 and 2,) so as to rock or turn easily on said shaft. At the rear end'is pivo'ted, by a pin, 35, a connecting-rod, 36, having its opposite end pivoted to the rear end of the footstep arm 37 by a pin, 38, and provided with the usual device, 39, for adjusting its length more or less.

The treadle arm 37 is mounted upon the shaft 40, which is secured in boxes 41 to each side of the frame.

42 is the foot-step.

To the forward end of the frame 34 is pivoted a shaft, 43, in bearings 44, and to the shaft 43 are rigidly secured two downwardly-pro jecting swinging arms, 45, having one or more friction-rollers, 46, pivoted between them so as to turn easily therein. 1

At the top of the front end of the frame 34 is rigidly secured,by a bolt, 49, a spring", 47, for holding the lower ends of the swinging arms 45 and the friction-rollers in toward the front of the machine. By means of this mechanism it will be seen that by pressing down on the treadle more or less the back end of the frame 34 will move up,while its forward end moves down, so as to bring the friction-rollers 46 down against the skin 48, (shown in Fig. 1,) and against the inclined face of the block 32, and thereby holdthe skin with more or less force while the stretching operation is going on.

The operation of the machine is as follows: Motion being given 'to the crank 15, in the direction of the arrow d, by means of a belt on the driving pulley, arranged in any wellknown way, a rocking movement is transmitted to the semicircular stretching-bar ,which oscillates back and forth a little less than onehalf of a revolution-enough less to prevent It is of the same semicircuand it will be drawn down over the stake? plate and stretched, as shown in the drawings in Fig. 1. On the return movement of the stretching-bar the skin should be drawn forward and out by the operator when released by the gripping device, then another portion put back, and the same operation repeated on another part of the skin or hide until the whole is completed.

The stretching force may be made greater or less, as hereinbefore mentioned, by more or less pressure upon the treadle, as in the judgment of the operator may be required.

For some kinds of light skins or hides the yielding block 32, the frame 34, its frictionrollers 46, and its foot-step and connecting parts will not be required or used; but they are necessary for the heavier skins, and sometimes in thesame grade of skins there are some that do not require as much force to stretch them or soften them as the others. For other skins the yielding block and stretching mechanism alone may be used together without the frame 34. It is therefore adapted for all or any of the grades of skins of the class above mentioned.

I claim as my inventionl. In a stretching and softening machine,

the combination of a semicircular or curved stretching-bar mounted on a shaft in bearings on the frame and having at its under plane portion an opening to receive a portion of the skin, mechanism, substantially as abovespecified, for gripping, holding, and releasing the skin and for giving the semicircular stretching-bar its oscillating movements, andastakeplate secured to a stake-post on the frame of the machine for alternately gripping, stretching, and releasing the skin during the process of stretching and softening, as above described.

2. In a stretching and softening machine, a. curved stretching-bar mounted on a shaft in bearings on the frame and having an opening to receive the skin, and mechanism, substantially as specified, for-gripping, holding, and releasing it, in combination with an arm rigidly secured to the shaft and connected by a connecting-rod to a crank for giving it an oscillating motion, a stake-plate secured to the machine, a yielding block facing the stakeplate and having an outwardly-inclined face over which the skin is drawn during the operation of 'stretching andsoftening, a vertical shaft upon which the yielding block is mounted, set in bearings in the frame, and a spring for ICO IKO

supporting the block, substantially as deers 46, and a trcadleand connecting-rod for scribed. Y operating it, a stake-plate, and a yieldinging 3. In a stretching and softening machine, @lined-faced block supported on a vertical lthe combination of a curved stretching-bar shaft in bearings on the stake-post, and a spi- VI5 5 supported on a shaft on lthe frame of the ma ral spring, 33, substantially as and for the purchine and having an opening to receive the poses described.

` skin and mechanism for receiving, holding and 7releasing it, substantially as above de- WILLIAM' M HOFFMAN scribed, an arm and connecting-rod connect- Witnesses:

1o ing it with a crank for giving it an oscillating JAMES SANGSTER,

motion, a frame, 34, carrying the friction-roll- CHARLES SANGSTER. 

